Notably, the presence of soluble NOX2-derived peptide (sNOX2-dp), a marker of NOX2 activation, is increased in the circulation of patients with pneumococcal pneumonia (Violi et al., 2015; Violi et al., 2020) and in those with peripheral artery disease (Loffredo et al., 2013). This evidence concerns the gene CYBB and pneumococcal pneumonia.